THE MORE THINGS CHANGE, THE MORE WE APPRECIATE THE FIRST THANKSGIVING

New England today has more students roving its campus groves than there were Indians in the time of the Pilgrims. Where Squanto helped the first settlers plant corn, public television's "Victory Garden" now guides novice gardeners. New Englanders Julia Child, Madeleine Kamman, and Jacques Pepin have Frenchified, Californiafied, Japonaised, and Chinoised the simple roasts, puddings, and other once-simple fare of the region. Culinary schools are as numerous as the old Indian trading posts.

Food writers today are more apt to maintain second residences in California than in Europe. They take their manner of cooking to health clinics for checkups; they no longer just hobnob with Guide Millau's master chefs, but collaborate with cardiologists and nutritionists.Half the first Plymouth colonists starved or froze the first winter. Today, hypermarkets fly in produce from every continent.

Change has come not only in the how and what of American eating, but in the where and why as well. Restaurants and workplace commissaries serve more meals, the family dining room fewer. A fracturing of family units and the dispersal of friends around the country have had an impact on the opportunity and obligation of getting together for holidays.

The abundance of choices of what to and how to eat, and the decline in occasions, mean that Americans have to think a bit harder at times like Thanksgiving, to discern the significance of the event.

Americans have long felt a certain ambivalence about Thanksgiving. It really represents not just a celebration of abundance, but gratitude for having traversed a period of testing.

Both the hardships and the triumphs of Thanksgiving are a continuing part of the American experience.

The first thanksgiving was declared by William Bradford, the new governor of Plymouth Plantation, in November 1621. He describes the first plentiful harvest in a history of the New England colony that he began to write at the end of the 1620s. Bradford's bucolic passage, "The first Thanksgiving" - an inventory of waterfowl, venison, cod, and corn - follows after a narrative of an opposite kind, which records the first winter in the New World. That passage is subtitled "The starving time." Even before that, so daunting was the prospect of stepping off onto the rigorous wilderness shore that, historians believe, Bradford's wife, Dorothy, flung herself overboard and drowned during the first weeks the Mayflower moored off Plymouth.

Thanksgiving was thereafter observed sporadically in the New World communities, until George Washington followed the exalting ordeal of the Revolution by declaring the first national Thanksgiving Day in 1789. Abraham Lincoln revived the holiday in 1863, during the Civil War. And Franklin D. Roosevelt, on the eve of World War II, moved the holiday to the third Thursday in November - and Congress in 1941 set the date for the fourth Thursday.

This Nov. 24, there will be as many distinct Thanksgivings as there are families, clusters of roommates, boarders, singles' households and homeless in America.

For some, the Norman Rockwell feast for a happy extended family, from Gramps to the newest-born, will be repeated. Other extended families are finding themselves divided at holidays by America's economic restructuring - as farms are sold, jobs beckon offspring hither and yon, and retirement communities continue to expand from Phoenix to Key West.

As long as people move about, the poignancy of family division, the absence of members on holidays, goes with them.

Nor is life in America universally easy. The descendants of the Indians Bradford knew in Plymouth still have not made full social and economic peace with the white newcomers. Some early searchers for religious freedom would later deny it to others. But Thanksgiving remains a choice: a decision not to dwell on the cup half empty, but to be grateful for the cup half full.